Closure for pressurized fluid tank



Oct. 12, 1965 A. B. HOLMES 3,211,321

CLOSURE FOR PRESSURIZED FLUID TANK Filed Feb. 18, 1963 3 Sheets-Sheet l 2 INVENTOR.

ALLIE B. HOLMES Semmes & s mmes A T TORNE Y5 Oct. 12, 1965' A. B. HOLMES 3,211,321

CLOSURE FOR PRESSURIZED FLUID TANK Filed Feb. 18, 1963 3 Sheets-Sheet 2 INVENTOR.

ALLIE B. HOLMES Semmes & Semmes A T TORNE Y5 Oct. 12, 1965 A. B. HOLMES 3,211,321

CLOSURE FOR PRESSURIZED FLUID TANK Filed Feb. 18, 1963 3 Sheets-Sheet 3 I60 I I m, I I II 1 I28 I T BIG 2 I I26 ll4 i I I 252 z 250 I I 244 2l6 I 244 2 2% I I v I i I I 228 3M 'I II I I a,

)7 II, ,I/ 3'0 I70 302 INVENTOR.

ALLIE B. HOLMES BY Mes Mes A T TOR/VEYS United States Patent 3,211,321 CLOSURE FOR PRESSURIZED FLUID TANK Allie B. Holmes, R0. Box 698, Mathis, Tex. Filed Feb. 18, 1963, Ser. No. 259,088 15 Claims. (Cl. 220-44) This invention is concerned with novel closures for tanks containing pressurized liquids. In particular it concerns closures which need not be removed for inspection of the fluid level and those by which maximum operating pressure may be regulated.

In recent years, there has been a trend to increase operating pressures in cooling systems. New, higher tensile strength metals allow construction of cooling systems which are able to stand increased operating pressures without adding weight or bulk to strengthen the equipment. Greater pressures allow greater temperature variance between the hot and cool conditions of the coolant, providing more efficient use of cooling equipment. Increased pressures also insure that the coolant will operate as a relatively high density liquid rather than a low density, ineflicient gas.

In order to inspect the coolant level, a high pressure cooling system must be cooled to a temperature which reduces the internal pressure to ambient conditions. If the system is not cooled, pressure contained therein usually blows coolant out of the reserve tank when the cap is removed. Upon release of pressure, heat in the system changes part of the coolant to a gas or steam, often with violent effects, resulting in danger to operating personnel and loss of coolant.

The hot erupting coolant is always at a temperature at which it may cause serious burns to inspectors. If the entire cooling system is exhausted, the operating equipment will be endangered and the coolant must be replenished, disturbing the temperature balance of the system and causing ineflicient operation of the equipment. Coolant loss and the time involved in replacing it, represent added operating costs.

Undesirable effects of inspecting pressurized cooling systems are particularly noticeable in automobiles. Operating pressures are often twice the normal atmospheric pressures. Consequently, when the coolant level is checked at a service station after driving a few or several miles, steam and water are blown out of the radiator top tank upon removing the cap. Without exception, service station attendants recognize danger in checking the coolant levels. Quantities of fluid lost vary, of course, with the pressure in the system before its opening. The replacement of the additive or coolant loss always represents an expense to the owner of an automobile. A further disadvantage is that all of the coolant cannot be replaced until the system has cooled to the ambient temperature. Seldom does the operator of an automobile take the necessary time to completely replenish the system. As a result, he leaves the gas station with a less eflicient cooling system than that with which he entered.

This invention overcomes the danger and loss of time involved in the inspection of pressurized cooling systems by allowing the level of coolant to be observed through a viewing window in the tank closure.

Accordingly, it is an object of this invention to provide a liquid level inspecting cap for a pressurized system.

Another object of this invention is to provide a combination liquid level viewing cap and adjustable pressure relief cap for a pressurized tank.

Referring to the drawings:

FIGURE 1 is an exploded view of the components of the preferred embodiment of the invention;

FIGURE 2 is an isometric view of the receiver;

FIGURE 3 is a side elevation of the assembled components in their operational relationship;

FIGURE 4 is a plan view of the assembled components of the cap, with a cut-away showing the connection between receiver and cap;

FIGURE 5 is an enlarged view of the stepped-tooth cam, positioned for minimum operating pressure;

FIGURE 6 is an enlarged view of the step tooth cam, being adjusted for an intermediate pressure limitation;

FIGURE 7 is an exploded view of the components of a second embodiment of the invention. Viewer 210 has been rotated clockwise from the position of viewer in FIGURE 1 in order to more clearly illustrate the sloped face of the lower portion;

FIGURE 8 is a plan view of the assembled components of FIGURE 7;

FIGURE 9 is a side elevation of the components, assembled in their operational relationship.

FIGURE 10 is a cross-section of the assembled components of the embodiment shown in FIGURES 1 through 6;

FIGURE 11 varies from FIGURE 10 in two ways: first, a higher operating pressure has been selected by respectively turning the elements of the stepped-tooth cam, and, second, an over pressure condition is present within tank 302, which causes the viewing assembly to rise from its seat;

FIGURE 12 is a cross-section of the assembled components of the second embodiment of the invention, shown in FIGURES 7 through 9;

Referring to FIGURES 1, 2 and 3, the assembly, generally indicated by the numeral 100, comprises viewer 110, resilient member 120, bearing plate 140, cap 150 and Viewer retaining ring 160. Rubber washer 170 stretches over lower portion 112 of viewer 110 and abuts the intermediate flange 114. The entire assembly fits inside receiver 310, which is welded about an aperture in tank 302. When cap 150 is locked to receiver 310, the tank aperture is sealed by washer 170.

The viewing element is generally indicated by the numeral 110. An integral flange 114 surrounds viewer 110 intermediate its ends, dividing viewer 110 into upper and lower portions. The lower portion 112 of the viewer depends into the tank, preferably taking the form of a cylinder which has been cut by a oblique plane. The upper portion 116 of the viewer has internal lugs 118, which cooperate with clamps 164 of snap ring 160 to retain viewer 110 in cap 150. Clamps 164 extend inwardly over the top of viewer 110 and lugs 118. At their innermost limit, clamps 164 are downwardly and reversedly bent to engage the lugs.

The pressure limiting element, generally indicated by the numeral 120 comprises a flexible body, coil spring 128 and pressure adjusting member 130. The flexible body has a center portion 122, which fits between the coils of spring 128 and upper portion 116 of viewer 110, and which terminates in flanges 124 and 126. Body 122 slips over upper portion 116 of viewer 110 in a tightly fitting manner, lower flange 126 abutting viewer flange 114. Upper flange 124 bears upon annular plate 140, which is soldered inside crown 151 of cap 150. Pressure relief coil spring 128 is closely wrapped around central portion 122 of the flexible body between flanges 124 and 126. When pressure within the tank is sufficient to compress spring 128, the tank is opened to the atmosphere.

In order that the cap may be suitable for use in tanks having diiferent operating pressure limitations, a stepped washer-cam 130 is used to bias spring 128 to a desired resilience. As illustrated in FIGURE 5, lower elements 132 and upper element 134 of cam 130 are locked in the position that would yield the lowest operating pressure. In FIGURE 6, a greater pressure limit had been selected by separating the elements 132 and 134, rotating them clockwise, and re-engaging their teeth. Thus spring 128 would be compressed and a higher tank pressure would be required to overcome the spring and unseat the seal. It may be seen that any degree of adjustment may be provided within the physical limits of the stepped cam washer.

Receiver 310 is soldered to the tank so that aperture 312 is communicant with the interior of the tank. Receiver 310 comprises an overflow port 314, and outward extending flange 315 at its top, and two similar downward extending ramps 316 at opposite sides thereof.

The entire cap assembly 100 fits inside receiver 180 with the exception of cap 150. Cap 150 has lugs 154 (illustrated in the cut-away views of FIGS. 3 and 8), which extend downward and inward to cooperate with ramps 186 of receiver 180. When the cap assembly is pressed down and turned clcokwise, lugs 154 ride along the base of ramps 186 until the lugs engage knob 188. When the cap is in a locked position, spring 128 is compressed, forcing washer 170 into sealing contact with the base 183 of the receiver 180. An additional non-resilient seal is effected between cap bearing plate 140 and receiver flange 185. The latter seal insures that the interior of receiver 180 communicates with the atmosphere only through overflow port 184. Excessive pressure within the tank acts upon gasket 170 and flange 114 to lift viewer 110 against the force of spring 128, unseating Washer 170 and allowing coolant to pass into receiver 310 and through overflow port 314.

Since cooling systems normally are not constructed of sufficient strength to withstand negative pressures, a vac uum release check valve 190 (shown in FIG. 2) may be installed in the viewing element 110. Vacuum release valve 190 comprises pin 192, washer 194 and spring 196. Pin 192 penetrates viewer 110 through an aperture slightly larger than the pin. Washer 194 is retained between the external wall of the viewer and the head of pin 192. Spring 196 is held in compression between the inner wall of the viewer and the point on the end of the pin to which it is fixed. When pressure within the tank falls below ambient pressure, greater pressure within the viewer acts through the aperture, pushing washer 194 away from the viewer against the compression of spring 196. When pressures are equal or greater within than without the tank, washer 194 is biased against the viewer in a sealing relationship.

A second embodiment of the invention provides for method of pressure selection by increasing the distance between spring bearing plate 240 and cap 250, as illustrated in FIGS. 6, 7 and 8. Aperture 252 of cap 250 is threaded to receive the threaded upward extension 244 of bearing plate 240. When the elements 250 and 240 are relatively moved in a clockwise direction, the distance between the two is reduced, decompressing the spring and reducing the tank pressure required to overcome the spring force. Conversely, when the two elements are moved in a relative counter-clockwise direction, pressure on spring 228 is increased as is the operating pressure limit of the tank.

Unique apparatus for holding the viewer in engagement with the cap comprises an additional embodiment of the invention as shown in FIGS. 6, 7 and 8. The upward rising portion 216 of viewing element 210 is longer than in the embodiment shown in FIG. 1. Holes 218 near the upper limit of viewer 210 receive the ends of resilient wire 219 when the elements of the cap are assembled. Since the ends of spring 219 project over the aperture 252 of cap 250, viewer 210 may not be removed from cap 250 without first removing wire 219.

FIGURE 10 illustrates a cross-sectional view of the embodiment of the invention shown in FIGURES 1 through 6. Note that the stepped-tooth cam 130 is completely closed, selecting the lowest operating pressure within the tank. When pressure within the tank rises above an equilibrium with force applied by the spring 128, tank pressure will act upon washer 170 and flange 114 to lift the viewer, as shown in FIGURE 11, and the interior of tank 302 will communicate with exhaust port 314. In FIGURE 11, the stepped-tooth cam illustrates a setting for intermediate tank operating pressure. As can be seen in both FIGURES 10 and 11, clamps 164 of retaining ring extend over lugs 118, which are integrally formed on the upper portion of viewer 110.

FIGURE 12 is a cross-section of the assembled elements of the second embodiment of the invention. Pressure within the tank is below an adjusted maximum. In FIGURE 13, pressure within the tank has risen to a point above the adjusted maximum. Accordingly, spring 228 is compressed and the interior of the tank communicates with overflow port 314.

Although the invention has been explained by way of specific examples, it would be obvious to one skilled in the art that the novelty is not limited to the elements described. Rat-her, the invention comprises a novel maximum pressure selecting cap, a novel means for coolant level inspection, and a combination thereof as set forth in the appended claims.

I claim:

1. Capping means for removably sealing an aperture in a tank comprising:

A. 'a receiver fixed to said tank, surrounding said aperture;

B. a viewer, positioned within said receiver;

C. a lid overlying said receiver and removably engaging said receiver;

D. compression means abutting said lid and said viewer, biasing said viewer into sealing relationship with said aperture; and

E. retaining means engaging said viewer and said lid, retaining said viewer, lid and compression means in assembled relationship.

2. The capping means of claim 1, additionally comprising anti-va-cuum means, comprising a perforation in said viewer, a stem extending through said viewer, a washer fixed to one end of said stem extending into said tank, a compression spring fixed to the opposite end of said stem, one end of said compression spring abutting said viewer about said perforation, whereby relative negative pressure within said tank forces said washer away from said viewer against source of said compression spring.

3. The capping means of claim 1, wherein said compression means comprises a yieldable tank pressure limiting spring, biasing said viewer into sealing relationship with said aperture, at tank pressures below a given value.

4. The capping means of claim 3, additionally comprising extensible pressure adjusting means interposed between said spring and one of said lid and said viewer, adjustably pre-selecting a given tank pressure.

5. Pressure relief means for removably sealing on an aperture in a tank, comprising;

A. a receiver fixed to said tank above said aperture;

B. sealing means positioned within said receiver;

C. a lid removably engaging said receiver;

D. resilient means, engaging said receiver and said sealing means and biasing said sealing means into sealing relationship with said aperture;

E. pressure-setting means, interposedly abutting said resilient means and one of said lid and said sealing means, adjustably biasing said resilient means;

F. retaining means, cooperating with said sealing means and said lid to retain said sealing means, in spaced relationship to said lid.

6. Capping means for removably sealing an aperture in a tank comprising:

A. an annular receiver fixed to said tank, surrounding said aperture;

B. an elongated transparent viewer having first and second opposite ends, said viewer having a laterally expanded portion intermediate said ends, one end of said viewer extending into said tank, said expanded portion of said viewer overlying said aperture;

C. a lid detachably engaging said receiver;

D. spring means abutting said lid and said viewer, biasing said lid and said viewer away from each other, and biasing said expanded portion into sealing arrangement with said aperture; and

E. retaining means, retaining said viewer in said lid.

7. Capping means for removably sealing an aperture in a tank comprising:

A. an annular receiver fixed at one end to a portion of the tank surrounding the aperture, said receiver describing at the other end an outward extending lip and at least one reversedly turned ramp;

B. an elongated, hollow, transparent viewer positioned in said receiver, said viewer having:

B1. a closed end projecting into said tank,

B2. an opposite, open end, extending beyond said receiver,

B3. an integrally formed flange extending laterally outwardly from said viewer intermediate its ends, said flange overlying said aperture,

C. a lid, overlying said receiver, said lid having a reversedly turned edge and inward extensions removably engaging said ramp, said lid further describing a central opening through which the open end of said viewer extends;

D. a coil spring surrounding a portion of said viewer intermediate said flange and said open end, said spring abutting said flange and an area of said lid adjacent the opening, thereby biasing said flange into sealing relationship with said aperture;

E. retaining means, overlying said lid, and engaging said viewer adjacent said open end, thereby retaining said viewer in said lid.

8. The apparatus of claim 5 wherein said pressure setting means comprises an extension screw.

9. The apparatus of claim 8 wherein said lid is threaded to cooperate with said screw.

10. The apparatus of claim 5 wherein said pressure setting means comprises cooperating stepped tooth cams.

11. The apparatus of claim 5 wherein said pressure setting means comprises corresponding, inverted stepped tooth cams.

12. The apparatus of claim 5 wherein said sealing means comprises a viewer.

13. The apparatus of claim 12 wherein said resilient means comprises a coil spring.

14. The apparatus of claim 13 wherein said viewer comprises an elongated body, having an upper and lower portion and intermediate flange; said upper portion being closely fitted within said coil spring.

15. The apparatus of claim 14 wherein said sealing means comprises said viewer flange, and said lower por tion of said viewer depends into said tank.

References Cited by the Examiner UNITED STATES PATENTS 2,636,634 4/53 Flubacker 220--44 2,917,924 12/59 Messick. 2,865,531 12/58 Gorst et al 22044 THERON E. CONDON, Primary Examiner. 

1. CAPPING MEANS FOR REMOVABLY SEALING AN APERTURE IN THE TANK COMPRISING: A. A RECEIVER FIXED TO SAID TANK, SURROUNDING SAID APERTURE; B. A VIEWER, POSITIONED WITHIN SAID RECEIVER; C. A LID OVERLYING SAID RECEIVER AND REMOVABLY ENGAGING SAID RECEIVER; D. COMPRESSION MEANS ABUTTING SAID LID AND SAID VIEWER, BIASING SAID VIEWER INTO SEALING RELATIONSHIP WITH SAID APERTURE; AND E. RETAINING MEANS ENGAGING SAID VIEWER AND SAID LID, RETAINING SAID VIEWER, LID AND COMPRESSION MEANS IN ASSEMBLED RELATIONSHIP. 